The product is called inSync v4.0 and it resides on laptops as a 7MB agent which works in the background and backs up files to a server over network links. The 40MB InSynch server software can support up to 1,000 laptops and run on physical servers or as a virtual machine.

The laptop agent performs source-based deduplication, calculating a checksum fingerprint for blocks to be backed up and ignores the block if it has been backed up already. The server distributes its most recently-seen checksums to all the connected laptop clients, so individual client laptops get a global view. Druva CEO and co-founder Jaspreet Singh says that because inSync is app-aware as far as Microsoft's Outlook and Office are concerned it understands about things like mail headers and footers being repeated in multiple blocks inside a PST file and, unlike other reduplication products, can deduplicate them.

The software sniffs or checks what type of network connection the laptop has - VPN, LAN or WAN - and optimises the style of network transmission, with smart bandwidth throttling, so as to minimise the network burden. There is what Singh calls intelligent caching to ensure that inSync client-server communications are fast and efficient.

Laptop users can restore files or folders on self-service basis, with a search facility enabling them to look for , say, mails sent at a particular time or to a certain person etc. Singh said: "We can restore reduplicated data on the fly. Avamar does not have self-service restore." Files can be selected and examined by the user to see how they changed over time with a file at a particular point in time selected for restore.

When it was suggested that inSync has similarities to Apple's Time Machine backup, he said: "Time Machine does not have search; it doesn't have deduplication; and it's not application-aware."

Druva was founded in 2007 by people who came from Veritas. They saw a need for laptop backup facilities that reflected the fact that laptops were not stationary and couldn't have a backup regime based on a standard scheduled backup time and constant, reliable network connection. Likewise restore should not be based on file versions but on file changes over time; a continuous data protection scheme in effect. Instead the software uses what Druva calls "smart, opportunistic scheduling".

InSync functionality will be coming for iPhones and iPads later this year with an enterprise server backup product due in the 2011-2012 period.

The company is headquartered in Puna, India, with an office in Santa Monica and now one in London. Its products are sold in 28 countries, using a reseller channel. It is being funded by the Indian Angel Network and Sequoia Capital, the VC firm that funded Google and many other startups. One aspect of Druva's marketing pitch is that business laptops are very poorly served by backup software. Over 30 per cent of corporate data can reside on laptops yet Druva says 67 per cent of these laptops are not backed up.

It says 750,000 laptops were lost at US airports in 2009, so 67 per cent of them probably had no backup of their data. Other backup suppliers, Singh says, do a poor job. Veritas has an ageing and very cheap product. IBM is not active in this market at all and neither is CA. He says the Druva software just sits in the laptop and works and is better than all of them.

Druva's customer list includes NASA, Emerson Network Power, Xerox, Schlumberger, Stihl and, in the UK, Capita. The US Marine Corps also use Druva's software, particularly in Afghanistan where notebooks are threatened by an unusually severe set of risks. There are more than 450 enterprise installations.

Druva's inSync v 4.0 costs £60 per client license, with discounts for quantity, and £500 for the server software supporting up to 1,000 clients. ®